Bones to Ashes by Kathy Reichs

The discovery of a skeleton in Acadia, Canada, reawakens a traumatic episode for forensic anthropologist Temperance Brennan. Could the young girl's remains be those of Evangeline Landry, Tempe's friend who disappeared when Tempe was twelve?  Exotic, free-spirited, and slightly older Evangeline enlivened Tempe's summer beach visits.... then vanished amid whispers that she was "dangerous."  Now, faced with bones scarred with inexplicable lesions, Tempe is consumed with solving a decades-old mystery-while her lover, detective Andrew Ryan, urgently needs her attention on a wave of teenage abductions and murders.  With both Ryan and her ex-husband making surprising future plans, Tempe may soon find that her world has painfully and irrevocably changed once again.